Circuit-controlling device



y 9, 1929- J. M. PESTARINI 1.720.566

CIRCUIT CONTROLLING DEVI CE Filed Oct. 10, 1927 O i a o "L.

I 0 l9 /8 I3 I Inventor:

Joseph M- Pesbar-ini,

His p oreg.

Patented July 9, 1929.

UNITED s'rarss PATENT OFFICE.

JOSEPH M. PESTARINI, OF ST. OUEN, FRANCE, ASSIGNOR TO GENERAL ELECTRIC COM- PANY, A CORPORATION OF NEW YORK.

CIRCUIT-CONTROLLING DEVICE.

Application filed October 10, 1927, Serial No. 225,114, and in France Octoberv 23, 1926.

The invention relates to circuit-controlling devices and has for its principal object the provision of a circuit interrupter capable of quickly interrupting the circuit when the 5 current has a tendency to increase suddenly in order to protect electrical apparatus such as motors, generators,transformers, or the like, connected in the circuit.

More specifically the preferred form of the present invention provides a circuit-interrupter having a magnetizing winding of high reactance to the terminals of which is connected a circuit of relatively low reactance having a movable current-conducting member included therein which is subjected to a combination of electro-dynamic forces to effect rapid operation of a contact to interrupt the circuit when the current tends to increase rapidly. With this arrangement the current through the magnetizing winding is not materially varied upon the sudden increase of current in the circuit due to the high reactance thereof. The low reactance circuit including the movable currentconducting member, however, is traversed by a relatively large current. The electrodynamic reaction of the current flow through the movable. current-conducting member with a'magnetic field produces a very-rapid movement thereof to operate the switch member associated therewith to the circuitopening position. The magnetic field for effecting operation ofthe movable currentconducting member preferably is setup by the high reactance magnetizing winding.

In addition, the movable current-conducting member is disposed in close proximity to a second current-conducting member with ductor and theobtained.

In the accompanying drawing, Fig. 1 illustrates in simplified diagrammatic form, a circuit-interrupter embodying the invention; Fig. 2 is a detailed representation of a preferred arrangement of the operating curthe connections arranged so that a strong repulslon between the movable current-consecond current-conductor 1s v as shown diagrammatically comprises the spaced apart contacts 10, 11, and the cooperating bridging contact 12. The bridging contact 12 is mechanically connected with a movable current-conductor 13 which is made very light so as to permit'rapid operation thereof. The movable current-conductor 13 and the magnetizing winding 14 having the magnetic structure 15 for providing a high reactance, are connected in multiple in the circuit Li, L controlled by the contacts 10, 11, and the bridging member 12of the interrupter. The movable current-conductor branch of the parallel circuit is made of'relatively high resistance as compared to the branch containing the magnetizing winding 14. Hence under stable conditions of current flow the value of the current through the movable conductor branch is only a small part. of the current through the magnetizing winding.

In order to effect operation of the circuitinterrupter the movable current-conducting member 13 is subjected to an electro-dynamic.

action. The electro-dynamic force for operating the movable current-conductingmember 13 may be obtained in the manner illustrated in Fig. 2. I In this figure the conductor 16, which is connected to thecontact 11 of the circuit-interrupter is disposed in close par- 7 allel alignment with the movable currentconducting member 13, which is electrically and mechanically connected with-the bridging contact 12. Preferably the conductor 16 and the movable current-conducting member 13 are formed of triangular cross sectional shape as shownin Fig. 3. This permits the conductors to be located closely adjacent each other so as to obtain the maximum repelling electro-dynamic action therebetween. movable current-conducting member 13.. is pivotally mounted at 17 so that it may carry th e bridging member 12 out of engagement with the contacts 10 and 11 when repelled from the conductor 16. In addition to the electro dynamic repel- The ling action exerted upon the current-conducting member 13, the member also may be disposed in astrongmagnetic field in order to increase the rapidity with which the" bridging contact 12 isoperated. Fig.4 shows the construction of a circuit-interrupter in which the movable current-conducting member .13 connected with the movable bridging member 12 is subjected both to the repelling action of the conductor 16 and the reaction with a magnetic field. The magnetic field is provided by means of the magnetic structure 15, which is associated with the magnetizing winding 14. The pole faces of the magnetic structure 15' preferably are located on either side of the movable current-conducting member 13, as indicated in the drawing. The magnetizing winding 14 may also be provided with a separate magnetic circuit 15 for producing a high reactance in the winding. As shown in Fig. 4, the movable current-conducting member 13 is supported by the resilient spring 18 so as to hold the bridging contact 12 in engagement with the spaced apart contacts 10 and 11. The pressure of the spring 18 upon the movable current-conducting member 13 may be regulated or entirely eliminated by means of the lever 19.,

The operationof the circuit-interrupter shown in'Fig. 4 is as follows With the bridging contact 12- in engagement with the contacts 10 and 11, a circuit is completed for the flow of current through the interrupter in the directions indicated by the arrows L L The current flowing in the terminal conductor L divides between the movable current-conducting member 13 and the magnetizing winding 14 in accordance with the relative resistance of the elements under stable current conditions. As previously pointed out, the resistance of the movable current-conducting member 13 is large with respect to the resistance of the magnetizing winding 14. Consequently, the ma'or por- -tion of the current flows through t e magmember 13. The conductor 16 carries the.

total current. The resulting electro-dynamic repelling action betweenthe conductor 16 and the movable current-conducting member 13, together with the reaction of the increased current flowing through the movable current-conducting member 13 with the magnet-icfield set up by the magnetizing winding 14, causes a very rapid operation of the movable current-conducting member 13 to carry the bridging contact 12 out of'engagement With the contacts 10 and 11. This rapid disengagement of the bridging .member 12 serves to interrupt the circuit and thereby protect electrical translating devices 'connected in the circuit L L such as motors, generators, or the like. With the spring 18 efie'ctive, the movable current-conducting member 13 and the bridging contact 12 are biased to the position in which they are shown in the drawing. In this case, the circuit would be interrupted only temporarily and the bridging contact would automatically return to the circuit closing position. In case the spring 18 is rendered inefiective by operation of the lever 19, the bridging contact 12 and the movable current-conduct ing member 13 will remain in the circuitopening position.

What 1 claim as new and desire to secure by Letters Patent 01 the United States, is

1. An electroresponsive device comprising a movable current conducting member, a second current-conducting member disposed in cooperating relation with said first member to set up an elcctm-dynamic force for operating the first member upon current flow through the said members, and means for setting up a magnetic field in cooperating relation with said movable current-conducting member to increase the speed of operation thereof upon said current flow through said movable member.

v 2. An electroresponsive device comprising means for setting up a magnetic field, a movable current-conducting member disposed in said field to be operated upon current flow in the member, and a second current-conducting member cooperating with said first member to set up an electro-dynamic force for increasing the speed of operation of said movable member upon said current flow therein. p 3. An electroresponsive device comprising a movable current-conducting member, a second current-conducting member cooperating with said first member toproduce an electrodynamic force for operating the movable current-conducting member upon current flow through said members, and an inductive device having a winding connected in shunt relation with said movable current-conducting member and in series relation with said second current-conducting member for increasingthe speed of operation of the movable member upon said current flow.

4. A circuit-controlling device comprising a pair of spaced apart contacts, a movable bridging member therefor, a relatively high resistance current-conducting member connected for movementwith the bridging mem- V 5. A circuit-interrupter comprising a mov able switch member, a magnetizing winding connected in the circuit controlled by the switch member, a movable current-conducting' member electrically connected in multiple relation with said winding and disposed in the magnetic field of said winding and mechanicall connected with said switch member for e ecting operation thereof to the circuit opening position, a second current-conducting member connected in the circuit controlled by the switch and cooperating with said movable current-conducting member to set up an electro-dynamic force to eliect operation of the switch member to the circuitopening position upon a predetermined flow of current in the circuit controlled thereby.

6. A circuit-interrupter comprising a pair of spaced apart contacts, a bridging member therefor, a magnetizing winding connected to one of said contacts in the circuit controlled by the bridging member, a movable current- :onducting member electrically connected in multiple relation with said magnetizing vinding and disposed in the magnetic field of said winding and mechanically connected with said bridging member to elfect operation thereof out of engagement with said spaced apart contacts, and a conductor connected to the other of said contacts and disposed in cooperating relation with said movable current-conducting members to set up an electro-dynamic force therebetween for operating the bridging member out of engagement with the said spaced apartcontacts upon a predetermined flow of current in the circuit controlled by the interrupter.

7. A circuit-interrupter comprising a pair of spaced apart contacts, a movable bridging member therefor, a magnetizing winding connected to one of said contacts in the circuit controlled by the interrupter, a movable current-conducting member mechanically connected to the bridging contact and electrically connected between the terminals of said magnetizing Winding and disposed in the magnetic field of said winding to effect operation ofsaidbridgingcontact to the circuit-opening position upon a predetermined flow of current in the circuit controlled by the bridging member and a conductor connected to the other of said contacts and disposed in cooperating relation with said movable currentconducting member to set up an electro-dynamic force for increasing the speed of operation of the bridging contact member upon said predetermined flow of current in the circuit controlled by the bridging member.

In witness whereof, I have hereunto set my hand this 15th day of September 1927.

JOSEPH M. PESTARINI. 

